Method of malting



- iiiiuat METl-i'l.) @il MALTE'NG Eric Kneen, Elm Grove, and Harold E. Smith, Madison, Wis., assignors to Kurth ll/iating Company, Miiwanlree, Wis., a corporation of Wisconsin No Drawing. Filed Dec. 1, 1958, er. No. 777,195 11 Claims. Cl. 19S-'7tl) This invention relates tolcontrol of the germination of cereal grain and to improvementr of beer quality and brewery yield. More particularly this invention relates to control of barley germination in malting and to improvement of beer and brewery yield through use of the malt produced by the new control.

The malting process comprises the germination of a cereal grain and is generally effected by rst steeping the grain in water, allowing it to germinate under controlled conditions of temperature and moisture, and iinally drying the germinated grain to the point where growth is stopped. In the usual malting or germination process, for example in the malting of barley, rootlets are formed and grow to lengths up to about 1/2 inch and the acrospire or coleoptile lgrows to about the same length as the kernel. Considerable respiration occurs during malting coincident with the growth of the rootlets and acrospire. This invention relates to the control and/or inhibition in part, of the respiration and rootlet growth during the malting process.

During the germination process, for example the production of malt from barley, there is usually a loss of l5 to 20% by weight of the barley .including the respiration loss and loss due to rootlet growth. The rootlets are removed from the malt prior to its use so their weight represents -a loss, in the weight for weight conversion of barley to malt. It is important therefor to the economics of malting to minimize this loss of Weight due to respiration and rootlet growth, and to obtain as high a yield of malt as possible from a given amount ot barley.

It is the primary object of this invention to treat the cereal grain during germination with a substance which inhibits the rootlet growth and restricts the respira-tion without decreasing the quality of the resulting germinated ber-October 1957) told of an additional eiiect of bromate in the steep water, mainly, restriction of rootlet formation and restriction of respiration. This would, of course, increase the yield of malt from `barley and would make the practice quite attractive. However, our studies dernonstrate a high residue of bromine (presumably bromide) is left in the malt and in the rootlets. Bromine and bromides are toxic (when tolerance levels are exceeded) and thus the use of bromates is undesirable. Macy and Sto-well attempted to use iodates and apparently thought about using chlorites to inhibit respiration and root growth but reported the iodate inetiective and apparently ruled out chlorites because of their known instability in solution.

Contrary to the iindings of Macy and Stowell, We have found that both potassium iodate and sodium chlorite are 'eective in inhibiting rootlet growth Aand/or respiration when added to germinating barley. We found it necessary to decrease the pH of the germinating barley from the usual about 5.6 to about 3.7 with acetic acid before potassium iodate became effective as an inhibitor. Sodi- J fs A.. i Y 'mi .i o Si@ aies idater ine um chlorite, on the other hand, we found to be very effective and useful as an inhibitor without any special adjustments. Since bromates are undesirable because they leave,

high residues of bromine in the 'finished products, and iodates are relatively costly for the savings eected in the process, sodium chlorite appears to be greatly advantageous as a germination control agent since it is relatively cheap, easy to apply, effective, and leaves no suspicious residue.

Examples of the use of sodium chlorite for the improvement of yield (decrease of malting loss) during the malting of barley are given in 'the following:

Example .L -Samples of barley (5,000 g.) were treated With 500 ppm. '(parts per million parts of barley treatn ed-i.e`. 500 pounds sodium chlorite per 1,000,000 pounds barley which is close to 21/2 pounds per 100 bushels) of sodium chloride by the addition of sodium chlorite solution at the designated time during the melting. The control barley was treated with an equal weight of water.

The results in Table I show signilicant and commercially important reductions in mialting loss with the use of sodium chlorite. The reduction eected by'treating in the last steep is not as great as the others, since the excess steep water is drained oit the barley, it is more wasteful of the chlorite. Hence, it is preferred to treat the barley in 4the germination period (malting) and better results were obtained when the treatment was after one day instead of after two days.

Example 2.-Another test, results shown in Table Ill Showed the relative effect of the quantity of sodium chlorite on malting loss. Samples of 2,500 g. each of barley were treated with the indicated level of sodium chlorite 'after the first day of melting. The results in Table Ill also show the malting losses when the various levels of sodium chlorite are added to the samples of barley after the second day of malting.

Table lIl Level of ehlorite treatment Control 50 p.p.m. 100 ppm. 300 ppm.

Percent malting loss -k.-

Table III Level of chlorite treatment Control 50 ppm. 100 p.p.m. 300 ppm.

Percent malting loss 15. 68 15.60 15. 77 15. 52

Consideration of Tables lII and lll forties the conclusio-n reached with respect to Table I that the treatment after one day is better than treatment after the second day. The tests also show the higher concentrations give better results with the exception that in both tests the p.p.m. solution produced poorer results than the 50 p.p.m. solution or than `the control which was, of course,

Patentes nec. as, resi amasar untreated. No explanation for this performance is suggested.

Example 3.-Sarnples of barley were treated with various levels of sodium chlorite in the manner illustrated in cost, ease of use, and does not leave residues of quesin preceding examples. The object of this particular test 5 very eiectively, however, by the use of ammonium nitrate. was to ascertain the eiect of high levels of sodium chlorite The end use of a large percentage of malt is in the on the llavor and other qualities of the inislied malt. 'In brewing process and adequate data indicates that v250 general, it was found that the sodium chlorite-up to 50G ppm. is satisfactory from a brewing quality standpoint ppm. did not atleet the chemical properties of the malt (as Well as 2G() ppm. or less) in that taste is no problem. and that the resulting mal-t `reacted in the usual manner l These investigations also indicate that the beer stability in the production of beer, etc. It was found, however, and brewery yield are improved markedly when using that the ilavor of the malt itself was degraded when levels chlorite treated malt in the brewing process. of sodium chlorite as high as 500 ppm. were added to Example 6.-Malts were prepared using chlorite at the germinating barley. The eiect of the sodium chlorite various levels sprayed on the barley immediately after treatment and the usefulness of other added materials such l5 steeping. These malts were then brewed in the customary as sodium carbonate, dextrose, and ammonium nitrate in fashion in a li barrel pilot brewery with the results shown counteracting the ol-avor are shown in Table IV. in the following Table Vl.

Table 1V Table VI 20 Additives p.p.m. Treatment Ammo- Dextrose nium Malt flavor Sodium Sodium nitrate Brewing performance Chlorite at indicated level chlorite carbonate Water only 0 0 0 0 G od 25 lppm. 2001).p.m. 2501).p.m.

O i o o o o Do. 500 0 t) D Bitter after taste. Brewery yield 72. G 73. 2 73. 8 74. 0 500 500 0 0 Very slightly bitter; Filtration Normal Normal Normal Normal 500 0 500 0 Do. Kettle break-.. Normal Normal Normal Normal 50D 0 U 500 Good. Fermentation. Normal Normal Normal Normal Beer avor. Normal Normal Normal Normal l Beer Foainw. Normal Normal Normal Normal The results in Table lV indicate that the bitter after- Beegtllsltgxm l 105 54 45 42 taste associated with higher levels (500 ppm.) of sodium 30 (pgs heat ilgg'gfg' chlorite can be counteracted with the addition to the Ch i 420 384 340 335 e0 days heat plus 3 days germinatmg barley, simultaneously with the sodium anw sa 321 249 isa 264 chorite, 500 p.p.m. of ammonium nitrate or, to some exl tem, by the addition 0f 500 11pm. SOdLlm CalbOIlaC OT 1 Allstabilitynumbersarehazereadingslnnephlos units-thohigher dextrose maar@ tt mts at" n..

a w a sa t.; isisaver a -i e Example 4.-The results shown in Table IV indicate tmatmsnyiia o o e y y y that Sodium carbonate has Some beneficial action in 403;) 2%) days at 120 F. followed by 3 days at drinking temperaturc; Le.. counteracting the bitter after-taste of high levels of sodium chlorite. I Malting loss results shown in Table V, which These iesults demonstrte tiatfhe brewery yield m` were obtained when 5 O00 g samples of barley were creases with the level of cnloriie in the treatment of the treated after the steeping with the indicated levels of barley This Vefy Important ecmlomlc .lmprqvemem has sodium chlorite and/or sodium carbonate. The results been Conlmed m a furthgr expenment m .Vhlch the COP' in Table V show that sodium carbonate by itself does not M01 man gave a brewery yleld of 68'0% Whlle the Chlone atleet the melting yield (does not lower the percent malttreated ma gave a ymld of, 692%' A ying loss) but seems to enhance the elect of the sodium Table VI ShGWS the resista?? ofd'he beerltodlthtype n ter chlorite i.e. he two substance are s ner Stic. of abuse 1t Iingm Twelve m t e tra e l? mar (e y .el

L S y g1 for the chlorite treated malts andthe resistance (stability) Table V y is improved with increasing levels of chlorite. This irnprovemerit may possibly be attributable to the oxidation 2.00 p pfm.. that has taken place in the malting process. Control msoogiiin' Qiiigiiin' sfiiiilsugiiocggf The very important improvement in stability and` chlorte carbonate Sodium brewery yield attributable to use of chlorite treated malt carbonate are added benefits and in no way alter the fact that the malt recovery is also enhanced by the chlorite treatment, m04 16,25 17m 1585 as in indicated by the malting loss data for the malts used in the experiment reported in Table VI. This malting Y .l l s dat i oiven in the followin table VII. Example 5 .-Two commercial size lots of barley (2,600 o s a s D g bushels per lot) were melted simultaneously under the Table V11 same conditions, with and without sodium chlorite treatment. The level of treatment was 200 ppm. sodium Treatment; Matting mss, chlorite added tour hours after the barley had drained pement from steeping. it was observed that the percent of the 17 O0 grains showing evidence of germination after 24 hours 65 gppm' @morue 16:56 was 78% for the sodium chlorite treated sample and 50% 200 ppm. eorlie gg for the control. The over-all malting loss was decreased 250 p'p'm c out@ by 1% when sodium chlorite was used.

From the preceding examples it can be concluded that It follows, therefore, that the chlorite treatment inthe addition of about 200 ppm. sodium chlorite to germicreases the yield of malt in the malting process and the hating barley, preferably during the irst 24 hours of maltuse of chlorite treated malts 1n brewing improves beer ing, is an effective way of increasing the malt yield. To stability and gives an economically important increase in our knowledge sodium chlorite is unique over other probrewery yield. posed chemicals for this use, in that, it is entirely practical Further studies along the lines suggested in the examples would, rio doubt, evolve further refinements and parameters `and for that reason this invention is to be limited only by the scope of the claims.

We claim:

l. A malting process including the steps of steeping, germination and kilning comprising the improvement of treating the grain with a solution of sodium chlorite after steeping has been completed and prior to kilning, whereby the rootlet growth and respiration of the barle grain is inhibited during the malting process.

2. The process according to claim 1 in which the treatment occurs during the iirst thirty-six hours of gerurination.

3. The process of claim l in which the solution also contains sodium carbonate.

4. The process of claim 1 in which `the solution also contains ammonium nitrate.

5. The process of claim l in which the solution contains an added material selected from the group consisting of ammonium nitrate, sodium carbonate and dextrose to control the iiavor of the malt produced.

6. The process of claim l in which the sodium chlorite level in the solution is between l0() andrSG() parts er million.

7. The process of claim 1 in which the sodium chlo- 6 rite level in the solution is between 200 and 500 parts per million.

8. A malting process in which the barley yrain is treated with a solution of Sodium chlorite in water between the steeping and kilning steps, the sodium chlorite level being between 200 and 500 parts per million.

9. The process of claim 8 invwhich the solution also contains sodium carbonate.

10. The process of claim 8 in which the solution also contains ammonium nitrate, the level of the chlorite being greater than G parts per million.

1l. The process of claim 8 in which the treatment occurs within the rst thirty-six hours of germination.

References Cited in the file of this patent UNITED STATES PATENTS DHeureuse July l1, 1876 Baker Iune 26, 1945 OTHER REFERENCES 

1. A MALTING PROCESS INCLUDING THE STEPS OF STEEPING, GERMINATION AND KILNING COMPRISING THE IMPROVEMENT OF TREATING THE GRAIN WITH A SOLUTION OF SODIUM CHLORIDE AFTER STEEPING HAS BEEN COMPLETED AND PRIOR TO KILNING, WHEREBY THE ROOTLET GROWTH AND RESPIRATION OF THE BARLEY GRAIN IS INHIBITED DURING THE MALTING PROCESS. 